The Rising Seas; The Oceans; Scientific American Presents; by Schneider; 8 Page(s)

Many people were awakened by the air-raid sirens. Others heard church bells sounding. Some probably sensed only a distant, predawn ringing and returned to sleep. But before the end of that day-February 1, 1953-more than a million Dutch citizens would learn for whom these bells tolled and why. In the middle of the night, a deadly combination of winds and tides had raised the level of the North Sea to the brim of the Netherlands's protective dikes, and the ocean was beginning to pour in.

As nearby Dutch villagers slept, water rushing over the dikes began to eat away at these earthen bulwarks from the back side. Soon the sea had breached the perimeter, and water freely flooded the land, eventually extending the sea inward as far as 64 kilometers (nearly 40 miles) from the former coast. In all, more than 200,000 hectares of farmland were inundated, some 2,000 people died and roughly 100,000 were left homeless. One sixth of the Netherlands was covered in seawater.